Volatile Organic Compounds and Esophageal Cancer: Understanding the Implications for Diagnosis and Treatment
While utilization of VOCs in the early detection of esophageal cancer has shown promise, future studies should aim at determining which VOCs would be the most specific in diagnosing GI malignancies.
One area of research in diagnosing esophageal cancer that is quickly developing includes the breath analysis of patients for certain volatile organic compounds (VOCs). VOCs are carbon-containing chemicals that can be eliminated through the breath as byproducts of their high vapor pressure leading to high rates of evaporation. Examples of VOCs include phenol, ethyl phenol, hexanoic acid, and methyl phenol.4
VOCs have been researched as potential cancer biomarkers in several gastrointestinal malignancies including esophageal, gastric, and colorectal cancer.4 Certain VOCs may be increased in patients with underlying malignancy based on increased levels of oxidative stress incurred by the cancer cells.4
Mass spectrometry has been used to analyze patient's breath for varying levels of VOCs and correlate them with potential risk and diagnosis of esophageal cancer. Kumar and colleagues found that patients with esophageal or gastric adenocarcinoma had significantly elevated levels of 12 VOCs compared with patients with Barrett's Esophagus or “normal” controls.2
These VOCs included pentanoic acid, hexanoic acid, phenol, methyl phenol, ethyl phenol, butanal, decanal, heptanal, hexanal, nonanal, octanal, and pentanal. In general, the most common parent VOC compounds found in patients with esophageal and gastric cancer include fatty acids, aldedhydes, and phenols. In addition to breath tests, studies have also evaluated the utility of detecting plasma VOCs in patients with esophageal cancer.5
Additional research is needed, however utilization of VOCs in the early detection of esophageal cancer has shown promise. Future studies should aim at determining which VOCs would be the most specific in diagnosing each type of gastrointestinal malignancy, including esophageal cancer. A relatively patient- and operator-friendly breath test (or blood test) that is affordable and accurate would have a positive affect in making esophageal cancer easier to diagnosis in the early stages when more treatment options are available.
- Baquet CR, Commiskey P, Mack K, et al. Esophageal cancer epidemiology in blacks and whites: racial and gender disparities in incidence, mortality, survival rates and histology. J Natl Med Assoc. 2005;97(11):1471-1478.
- Kumar S, Huang J, Abbassi-Ghadi N, et al. Mass spectrometric analysis of exhaled breath for the identification of volatile organic compound biomarkers in esophageal and gastric adenocarcinoma. Ann Surg. 2015;262(6): 981-990. doi: 10.1097/SLA.0000000000001101
- Vakil N, Talley N, van Zanten SV, et al. Cost of detecting malignant lesions by endoscopy in 2741 primary care dyspeptic patients without alarm symptoms. Clin Gastroenterol Hepatol. 2009;7:756-761. doi: 10.1016/j.cgh.2009.03.031